Surgical master-slave robot

ABSTRACT

Some embodiments are directed to a surgical master-slave robot for use in minimally (or reduced) invasive surgery on a subject. The robot includes an instrument manipulator for mounting of a surgical instrument, and a linkage system for moveably suspending the instrument manipulator. A first linkage component is configured for guiding a first suspension to move along a first movement trajectory. A second linkage component is configured for guiding a second suspension point to move along a second movement trajectory. The first movement trajectory and the second movement trajectory differ and are selected to provide a combined translational and rotational movement of the instrument manipulator which moves the instrument manipulator along a predefined trajectory from a surgical position to a standby position. The robot may provide a stable removal of the instrument manipulator during a surgery as well as sufficient surgeon&#39;s workspace after the removal of the instrument manipulator.

CROSS REFERENCE TO RELATED APPLICATION(S)

This application is a National Phase Filing under 35 C.F.R. § 371 of andclaims priority to PCT Patent Application No. PCT/EP2017/052103, filedon Feb. 1, 2017, which claims the priority benefit under 35 U.S.C. § 119of European Patent Application No. 16154172.7, filed on Feb. 4, 2016,the contents of each of which are hereby incorporated in theirentireties by reference.

BACKGROUND

Some embodiments relate to a surgical master-slave robot for use inminimally (or reduced) invasive surgery which includes an instrumentmanipulator and a linkage system for moveably suspending the instrumentmanipulator. Some other embodiments relate to a cannula connector forconnecting the instrument manipulator to a cannula.

Robotically assisted surgery with a master-slave system may assist asurgeon in performing a minimally (or reduced) invasive surgery.Typically, the slave system performs the actual surgery, by instrumentmanipulators which handle surgical instruments. The surgeon remains incontrol of the instruments by operating a master. A temporarily removalof an instrument manipulator from a surgical position proximate to asubject may be desired, for example, to make sufficient room for thesurgeon to perform surgery by hand. In some surgical operations, e.g.,eye surgery, the surgeon may need to accesses the subject for manualsurgery multiple times during the operation. Thus the temporarilyremoval of the instrument manipulator from the proximity of the subjectfor to perform manual surgery and then return of the instrumentmanipulator back to the surgical position to continue the minimally (orreduced) invasive surgery may be required multiple times during theoperation. Due to such repetitions, besides the requirement of providingsufficient room at the surgical position after the temporary removal ofthe instrument manipulator, a stable and quick removal of the instrumentmanipulator is often desired. When the removal is repeated multipletimes, stability of the removal may, in general, help to avoid damage tothe tissue under surgery and also to the robot. In addition, inemergency cases, a quick removal of the instrument manipulator may beparticularly advantageous or preferred.

US 20040261179 A1 describes a method and apparatus for the mounting ofsurgical setup arms to the table pedestal or floor below an operatingtable. The ceiling-height-mounted robotic arm assembly andbelow-table-mounted robotic arm assembly may be pre-configured to beready for surgery while the fixable set-up arms are disposed generallyclear of the personnel-usable space adjacent the operating table. Theceiling mounted setup arm is said to include at least oneparallelogram-link structure. Each parallelogram may be raised andlowered vertically, with minimal residual force, with gas springs beingselected to support the majority of the system weight throughout therange of motion.

A publication titled “Vitreo-retinal eye surgery robot; sustainableprecision, 2011, H. C. M. Meenink, PhD Thesis” describes a surgicalmaster-slave robot for use in minimally (or reduced) invasive surgery.The surgical master-slave robot of Meenink includes an instrumentmanipulator and a parallelogram linkage system for positioning theinstrument manipulator. The linkage system is configured to rotationallymove the instrument manipulator from a surgical position proximate to asubject to a standby position distal to the subject. During therotational movement, the instrument manipulator is suspended on asuspension point of the instrument manipulator via a linkage componentcoupled to the instrument manipulator.

SUMMARY

A disadvantage of the surgical master-slave robot of Meenink is that theinstrument manipulator is insufficiently stable during the removal ofthe instrument manipulator and, moreover, after the removal, theinstrument manipulator still remains in the surgeon's workspace ofmanual surgery through which the surgeon's hands move, or through whichinstruments are handed to the surgeon.

It would be advantageous to have a surgical master-slave robot whichaddresses at least one of the above disadvantages.

To better address this concern, a first aspect of some embodimentsprovides a surgical master-slave robot for use in minimally (or reduced)invasive surgery on a subject, the surgical master-slave robotincluding:

-   -   an instrument manipulator for mounting of a surgical instrument;        and    -   a linkage system for moveably suspending the instrument        manipulator, the linkage system including:    -   a first linkage component coupled to the instrument manipulator        at a first suspension point of the instrument manipulator;    -   a second linkage component coupled to the instrument manipulator        at a second suspension point of the instrument manipulator;        wherein:    -   the first linkage component is configured for guiding the first        suspension point of the instrument manipulator to move along a        first movement trajectory;    -   the second linkage component is configured for guiding the        second suspension point of the instrument manipulator to move        along a second movement trajectory; and wherein the first        movement trajectory and the second movement trajectory differ        and are selected to provide a combined translational and        rotational movement of the instrument manipulator which moves        the instrument manipulator along a predefined trajectory from a        surgical position proximate to the subject to a standby position        distal to the subject.

The above measures involve an instrument manipulator for mounting of asurgical instrument. Instrument manipulators for surgical master-slaverobots are known in the art per se. The instrument manipulator may be,for example, a mount. The instrument manipulator may be affixed to therobot and thereby take over the tasks of the surgeons hand by handlingand manipulating surgical instruments or surgical tools. A surgicalinstrument may be a specially designed tool or device for performingspecific actions of carrying out desired effects during a surgery oroperation, such as modifying biological tissues, or to provide accessfor viewing it. Examples of such surgical instruments include, but arenot limited to, forceps, mechanical cutters, coagulation cutters,scissors, injection needles, sealing devices, etc.

The above measures further involve a linkage system for moveablysuspending the instrument manipulator. Examples of linkage systems rangefrom the four-bar linkage used to amplify force in a bolt cutter or toprovide independent suspension in an automobile, to complex linkagesystems in robotic arms and walking machines. In a linkage system,linkage components such as bars (also referred to as links) may beconnected to one or more other links by, for example, pin joints (alsoreferred to as hinges), sliding joints, or ball-and-socket joints so asto form a closed chain or a series of closed chains. A linkage componentmay be connected to a body, e.g. an instrument manipulator, to suspendand/or move the body. The connection point of the body and the linkagecomponent may be referred to as a suspension point. In the presentrobot, the linkage system includes a first linkage component coupled tothe instrument manipulator at a first suspension point of the instrumentmanipulator. The linkage system further includes a second linkagecomponent coupled to the instrument manipulator at a second suspensionpoint of the instrument manipulator. Linkage systems, also referred toas linkages, are know in the art per se.

It is an insight of the applicants that, upon a temporary removal,sufficient room for a surgeon will be provided while at the same timethe instrument will remain compact and close to the surgeon to bereturned when desired, without restricting the surgeon's performance.This effect is achieved namely by providing the configuration andarrangement of the instrument manipulator and the linkage system andtheir coupling as claimed which enable a combined translational androtational movement of the instrument manipulator during arepositioning. As opposed to some embodiments, in the related art robotof Meenink the instrument manipulator is only rotated upon a temporaryremoval of the instrument manipulator which will result in aninsufficient working space. Rotating the system further away would solvethis problem, but may require more room for the system to rotate throughand will make the return of the instrument manipulator to the surgicalarea more difficult. This problem of the related art robot is solved inan inventive way by the applicants, by arranging the linkage system sothat a selected translational movement, which may refer to a rigiddisplacement without a rotation, is added to a selected rotationalmovement which enable a flexible in-plane as well as spatial movement ofthe instrument manipulator in any desired direction along a predefinedtrajectory. Here, the rotational movement may be established by eachsuspension point being guided along a differently shaped motiontrajectory, whereas same-shaped motion trajectories provide onlytranslation.

For example, the linkage system may be arranged to enable repositioningof the instrument manipulator by removing the instrument manipulator bya small-radius rotation and then moving the instrument manipulator by atranslational-rotational movement to a position outside the surgeon'sworking space, e.g., below the working space area. As such, sufficientspace will be provided for the surgeon to manually perform surgicaltasks while at the same time the robot remains compact and sufficientlyclose to the surgeon for convenient return of the robot back to thesurgical area when desired.

In addition to the above advantage, the applicants have the insight thatby the arrangement and the configuration of the instrument manipulatorand the linkage system of some embodiments, the instrument manipulatoris suspended on two suspension points during the movement. As a result,the robot and the instrument manipulator will remain stable during thetemporal movement. As such, the system may advantageously be lessvulnerable when moved away. Moreover, compared to a less robust andstable system such as that with one suspension point, the system withincreased stability may help to avoid inducing damage to the tissueunder surgery upon the removal. Moreover, by being guided along apredefined trajectory, the movement of the instrument manipulator may beconstrained to the trajectory, which facilitates assuming the surgicalposition from the standby position and vice versa. As such, theinstrument manipulator may be easily moved from its standby positionalong the predefined trajectory to the surgical position, e.g., toeasily (re)connect to a trocar. It is noted that the robust design ofthe robot according to some embodiments may be advantageous not only forthe removal of the instrument manipulator but also for accurate returnand repositioning of the instrument manipulator back to the surgicalposition to resume the robotic surgery. Stabilized instrumentpositioning may also enhance dexterity on surgical tasks and someembodiments, as such, discloses a more robust surgical master-slaverobot for use in minimally (or reduced) invasive surgery.

Optionally, the movement of the instrument manipulator causes a tip of adistal end of the instrument manipulator to move along a third movementtrajectory, wherein an end portion of the third movement trajectoryproximate to the subject is oriented in a direction perpendicular to asurgical entry surface of the subject. This is advantageous in that theremoval of the instrument manipulator from an entry site of the surgicalinstrument on the subject may be safer for the patient when theinstrument manipulator is removed in a substantially perpendiculardirection. Deviation above a threshold, e.g., 22.5° degrees, from thisperpendicular direction may damage a tissue of the subject upon removalof the instrument manipulator. For example, when the instrumentmanipulator is coupled to a cannula at a proximal end, substantialdeviations of the removal of the instrument from substantiallyperpendicular orientation, e.g., parallel to a central symmetry axis ofthe cannula, may exert lateral forces to the cannula which may beharmful for the patient. It is further noted that directions within therange of 90±0 degrees, 90°±2° degrees, 90°±5° degrees, 90°±10° or90°±22.5° degrees may be considered substantially perpendiculardirections for obtaining a safe removal of the instrument manipulator.

Optionally, the standby position is located laterally sideways withrespect to a sagittal plane of the subject and the linkage system isconfigured for guiding the instrument manipulator laterally sidewardwith respect to the sagittal plane during the movement from the surgicalposition to the standby position. Such repositioning of the instrumentmanipulator may advantageously result in the removal of the instrumentmanipulator from the area directly above the subject which may be animportant area for the surgeon, for example, in an emergency or toperform regular manual tasks during operations.

Optionally, the standby position is located lower than the subject andthe linkage system is configured for guiding the instrument manipulatordownward with respect to a coronal plane of the subject during themovement from the surgical position to the standby position.Advantageously, such repositioning of the instrument manipulator mayprovide further room to the surgeon to have access to the area aroundthe subject and the surgical entry site. For example, repositioning ofthe instrument manipulator below a subject may provide sufficient spacefor a surgical assistant to give surgical tools to the surgeon. It isnoted that repositioning may, in general, refer to a change in position,e.g., changing from the surgical position to the standby position orvise versa.

Optionally, the surgical master-slave robot includes a release mechanismfor holding and releasing the instrument manipulator at the surgicalposition; and the movement of the instrument manipulator is obtained asa result of force acting upon the instrument manipulator when therelease mechanism releases the instrument manipulator, the force beinggenerated by gravity and/or a preloaded spring. Such gravity and/orpreloaded spring actuated removal of the instrument manipulator isadvantageous in that it makes the removal more convenient as a surgeonor other personnel do not have to waste energy to accurately repositionthe instrument manipulator every time the removal may be required. Thiswould be particularly advantageous when the instrument manipulator maybe required to be removed multiple times during an operation. With suchgravity and/or a preloaded spring actuation, a separate electricalactuator, which may fail in case of, e.g., power failure, may not berequired. As such, the release mechanism may be more robust andreliable.

Optionally, the release mechanism includes a hook, a lock arm pin, and arelease actuator, wherein the hook is arranged and configured forgripping the lock arm pin; the lock arm pin being connected to one ofthe first linkage component, the second linkage component or theinstrument manipulator via a lock arm, and the release actuator isarranged and configured for releasing the hook from the lock arm pin. Bymoving the hook toward the lock arm pin, the hook may simply grip thelock arm pin and thereby lock the mechanism, and the lock may be simplyreleased by activating the release actuator, e.g., by way of pushing ahandle of the release actuator. As such, the described locking mechanismmay enable a quick and convenient release and repositioning of theinstrument manipulator when desired. Furthermore, such locking mechanismmay enable an accurate return of the instrument manipulator back inplace to the surgical working space to continue the operation tasks bythe surgical instrument when desired.

Optionally, the linkage system is provided with a manual actuationhandle for enabling a user to manually actuate the linkage system so asto move the respective suspension point of the instrument manipulatoralong the respective movement trajectory. This may allow convenientcontrol of a user of the movement of the instrument manipulator whendesired. By actuating the linkage system via the handle, an easy controlof the function of the linkage system may be advantageously obtained.

Optionally, the surgical master-slave robot includes an actuator foractuating the linkage system so as to move the respective suspensionpoint of the instrument manipulator along the respective movementtrajectory. Including the actuator may enable an automatic actuation ofthe linkage system and thereby an automatic control of the movement ofthe instrument manipulator.

Optionally, at least one of the first linkage component and the secondlinkage component includes or is constituted by a slider for slidingalong a guide shaped to establish the respective movement trajectory.Advantageously, the guide may simply provide the respective trajectoryfor the slider and the movement may be thus simply performed by slidingthe slider along the guide. Using sliders in the linkage system may be,in general, advantageous in obtaining a smooth and guided movement ofthe suspension points in the desired movement trajectories. A slider maybe, for example, a carriage which may slide on a track.

Optionally, at least one of the first linkage component and the secondlinkage component is a rod member rotatable about a rotation point and arotation of the at least one of the first linkage component and thesecond linkage component about the rotation point provides the movementof the respective suspension point along the respective movementtrajectory. Advantageously, various movement trajectories may beachieved simply by using rod members with different lengths.

Optionally, one or both of the first movement trajectory and the secondmovement trajectory are arc-shaped movement trajectories. Although themovement trajectories may have any shape, arc-shaped movementtrajectories may advantageously enable a desired rotation of theinstrument manipulator such that an optimal route for the movement ofthe instrument manipulator may be selected.

Optionally, the surgical master-slave robot further includes a cannulaconnector for coupling to a cannula, wherein the cannula provides anopening at the surgical entry surface of the subject for the surgicalinstrument to enter an interior of the subject, and wherein the cannulaconnector:

-   -   is coupled to the instrument manipulator at a proximal end;    -   includes a through passage for allowing the surgical instrument        to pass through the through passage; and    -   is shaped to fit a shape of the cannula so as to establish a        releasable coupling with the cannula which releases when the        instrument manipulator moves in the direction perpendicular to a        surgical entry surface of the subject.

Cannulas are known in the art per se. The cannulas may enable easyswitching between surgical instruments, making use of the same entrypoint without unnecessarily puncturing a tissue of the subject atmultiple places. Furthermore, the cannulas may provide a ‘safetyboundary’ between the surgical instruments and the tissue, protectingthe tissue. By using a cannula connector between the instrumentmanipulator and the cannula that is aligned with a longitudinal axis ofthe surgical instrument, sideways forces on the surgical instrument maybe prevented as the cannula connection may force the cannula to bealigned with the instrument manipulator and thereby with the surgicalinstrument.

Optionally, the cannula has a conical shape and wherein the cannulaconnector is conically shaped to fit the conical shape of the cannula.The conical shape may allow the instrument manipulator with the cannulaconnector to be easily positioned onto and aligned with the cannula. Theangle of the conical shape may be such that the cannula may not rotateunderneath the cannula connector such as a ball joint would.Furthermore, the angle of the conical shape may be such that the cannulamay be loosened easily when the instrument manipulator is excluded awayfrom the area for surgery. This may be particularly advantageous when aquick release may be required during the operation, e.g., due toemergency. It is also advantageous when the removal of the instrumentmanipulator is to be repeated multiple times during the surgery, e.g.,to allow a manual surgery by the surgeon.

It is noted that the conical shape may allow the instrument manipulatorto be put in place, even when the cannula is not aligned with thecannula connector. The cannula connector may guide and rotate thecannula such that the cannula aligns when the instrument manipulator isintroduced.

Optionally, the cannula and the cannula connector are rigidly coupled.Sufficiently stiff coupling may ensure sufficient stability andreliability of the connections between the cannula and the cannulaconnector and may minimize sideways deflections resulting frominteraction forces.

A further aspect of some embodiments provides a cannula connector asdescribed above.

It will be appreciated by those of ordinary skill in the art that two ormore of the above-mentioned embodiments, implementations, and/or aspectsmay be combined in any way deemed useful.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of some embodiments are apparent from and willbe elucidated with reference to the embodiments described hereinafter.In the drawings,

FIG. 1a shows a configuration of a linkage system for moveablysuspending an instrument manipulator of a surgical master-slave robot;

FIG. 1b shows a translational and rotational movement of the instrumentmanipulator obtained by rotation of a first rod member and a second rodmember in a clockwise of rotation;

FIG. 1c shows an example of an instrument manipulator and the linkagesystem of the surgical master-slave robot of FIGS. 1a -b;

FIG. 2a shows another configuration of a linkage system for moveablysuspending an instrument manipulator;

FIG. 2b shows a translational and rotational movement of the instrumentmanipulator obtained by rotation of a first rod member and a second rodmember in opposite directions of rotation;

FIG. 3a shows another configuration of a linkage system for moveablysuspending an instrument manipulator;

FIG. 3b shows a translational and rotational movement of the instrumentmanipulator obtained by rotation of a first rod member and a second rodmember in a counterclockwise direction of rotation;

FIG. 4a shows another configuration of a linkage system for moveablysuspending an instrument manipulator, wherein the first linkagecomponent is a slider and the second linkage component is a rod member;

FIG. 4b shows a translational and rotational movement of the instrumentmanipulator obtained by a rotation of the rod member and sliding of theslider along a substantially straight path;

FIG. 5a shows another configuration of a linkage system for moveablysuspending an instrument manipulator, wherein the first linkagecomponent is a slider and the second linkage component is a rod member;

FIG. 5b shows a translational and rotational movement of the instrumentmanipulator obtained by a rotation of the rod member and sliding of theslider along a curved path;

FIG. 6a shows a release mechanism for holding and releasing theinstrument manipulator;

FIG. 6b shows the release mechanism when a release actuator releases ahook of a quick release lock and thereby releases the instrumentmanipulator via a lock arm;

FIG. 7a shows an example of a configuration and construction of arelease mechanism;

FIG. 7b shows a 3D isometric view of the release mechanism; and

FIG. 8 shows a cannula connector for coupling to a cannula, the cannulaconnector providing a through passage for a surgical instrument.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

It this section, it should be noted that for the sake of explanation,the entire robot has not been shown and some features of the robot,e.g., the linkage system and the movement of the instrument manipulatorare explained in details. It is noted that the images show theinstrument manipulator to operate on a right eye. For surgery on a lefteye, the instrument manipulator may be positioned on the left side of apatient. In case of the left eye surgery, movements described herein maybe mirrored with respect to the sagittal plane of the patient. It isnoted that, in general, other tissues and organs may be the subject ofthe surgery and the robot is not limited to be used only in eye surgery.FIG. 1a shows a configuration of a linkage system 200 for moveablysuspending an instrument manipulator 210 of a surgical master-slaverobot. It is noted that the linkage system 200 and the instrumentmanipulator 210 are shown schematically and a cut through view in atransverse plane is shown. The linkage system 200 includes a firstlinkage component 220 coupled to the instrument manipulator at a firstsuspension point 202 of the instrument manipulator 210. The firstlinkage component 220 may be configured for guiding the first suspensionpoint 202 of the instrument manipulator 210 to move along a firstmovement trajectory. The linkage system 200 further includes a secondlinkage component 230 coupled to the instrument manipulator 210 at asecond suspension point 204 of the instrument manipulator 210. Thesecond linkage component 230 may be configured for guiding the secondsuspension point 204 of the instrument manipulator 210 to move along asecond movement trajectory.

FIG. 1b shows a translational and rotational movement of the instrumentmanipulator 210 obtained by rotation of a first rod member 220 and asecond rod member 230 in a same direction of rotation. The first rodmember 220 may be configured for guiding the first suspension point 202of the instrument manipulator 210 to move along the first movementtrajectory 260. The second linkage component 230 may be configured forguiding the second suspension point 204 of the instrument manipulator210 to move along the second movement trajectory 270. The suspensionpoint may be a point which couples the instrument manipulator 210 to thelinkage system 200 by, for example, bolts and nuts, a hinge, a shaft,etc. In the illustrated configuration, the first rod member 220 may beinitially in almost upright position, and the second rod member 230 maybe in an angle of about 60°. Here and in the following, the angles aredescribed with respect to 0° corresponding to a 3 o'clock position and90° corresponding to a 12 o'clock position, i.e., denoting acounterclockwise rotation.

Both rod members 220,230 may rotate clockwise until the second rodmember is substantially horizontal. With this configuration, a distaltip of the instrument manipulator or surgical instrument may berepositioned, for example, about 75 mm outwards and 70 mm downwards,moving the instrument manipulator 210 out of the surgeon's workspace 15in a compact way.

It is noted that, with the claimed arrangement and configuration, upon atemporarily removal of the instrument manipulator, sufficient room for asurgeon may be provided while at the same time the instrument may remaincompact and close to the surgeon to be returned when desired, withoutrestricting the surgeon's performance. This effect may be achievednamely by combining translational and rotational movement of theinstrument manipulator during the removal.

It is further noted that the first movement trajectory and the secondmovement trajectory differ and are selected to provide a combinedtranslational and rotational movement of the instrument manipulator 210from a surgical position proximate to a subject 10 to a standby positiondistal to the subject 10.

The standby position may be located lower than the subject 10 out of asurgeon's workspace 15 and the linkage system 240 may be configured forguiding the instrument manipulator 210 downward with respect to acoronal plane of the subject during the movement from the surgicalposition to the standby position. The standby position may be locatedlaterally sideways with respect to a sagittal plane of the subject andthe linkage system 240 may be configured for guiding the instrumentmanipulator 210 laterally sideward with respect to the sagittal planeduring the movement from the surgical position to the standby position.

FIG. 1c shows an example of the instrument manipulator and the linkagesystem of the surgical master-slave robot 100 of FIGS. 1a -b. It isnoted that the same reference numerals in FIG. 1c and FIGS. 1a-c referto the same corresponding components.

It is noted that FIGS. 1a -c, as well as FIGS. 2a -5 b, show atransverse view of the robot and the subject in a transverse plane. Forfurther clarification of the movement of the instrument manipulator withrespect to the subject 10 a sagittal plane 12 and a coronal plane 14 ofthe subject 10 are indicated in FIG. 1 a. It is further noted that thelinkage system may be coupled to a base 5 of the surgical robot which isschematically shown in FIG. 1 a.

FIGS. 2a -5 b, show alternative arrangements and configurations of thelinkage system and the instrument manipulator. Same or similar effectsand results provided by the arrangement and configuration of FIG. 1 maybe achieved.

FIG. 2a shows another configuration of a linkage system 300 for moveablysuspending an instrument manipulator 310. FIG. 2b shows a translationaland rotational movement of the instrument manipulator 310 obtained byrotation of a first rod member 320 and a second rod member 330 inopposite directions of rotation. The first rod member 320 may beconfigured for guiding the first suspension point 302 of the instrumentmanipulator 310 to move along the first movement trajectory 360. Thesecond rod member 330 may be configured for guiding the secondsuspension point 304 of the instrument manipulator 310 to move along thesecond movement trajectory 370. In the illustrated configuration, thefirst rod member 320 may be, for example, in almost upright position andthe second rod member 330 in an angle of approximately 135°. The firstrod member 320 may rotate clockwise, while the second rod membercounterclockwise.

FIG. 3a shows another configuration of a linkage system 400 for moveablysuspending an instrument manipulator 410. FIG. 3b shows a translationaland rotational movement of the instrument manipulator 410 obtained by arotation of a first rod member 420 and a rotation of a second rod member430 in a same direction of rotation. In the illustrated configuration,the first rod member 420 may be, for example, in horizontal orientationand the second rod member in an angle of approximately 135°. Both thefirst rod member and the second rod member may rotate counterclockwise.

FIG. 4a shows another configuration of a linkage system 500 for moveablysuspending an instrument manipulator 510, wherein the first linkagecomponent is a slider 520 and the second linkage component is a rodmember 530. FIG. 4b shows a translational and rotational movement of theinstrument manipulator 510 obtained by sliding of the slider 520 formoving a first suspension point 502 along a substantially straightmovement trajectory 560 and by a rotation of the second rod member 530for moving a second suspension point 504 along a second curved orarc-shaped movement trajectory 570.

FIG. 5a shows another configuration of a linkage system 600 for moveablysuspending an instrument manipulator 610, wherein the first linkagecomponent is a slider 620 and the second linkage component is a rodmember 630. FIG. 5b shows a translational and rotational movement of theinstrument manipulator 610 by a rotation of the rod member 630 and bysliding of the slider 620 along a curved path for moving a secondsuspension point 604 along a second curved or arc-shaped movementtrajectory 670.

It is noted that in the illustrated configurations of FIGS. 1a -5 b,movement of the instrument manipulator 210, 310, 410,510, 610 may causea tip of the instrument manipulator and/or a tip of the surgicalinstrument coupled to the instrument manipulator to move along a thirdmovement trajectory 280, 380, 480, 580, 680. An end of the thirdmovement trajectory proximate to the subject 10 may be in a direction290, 390, 490, 590, 690, 790 substantially perpendicular to a surgicalentry surface of the subject 10. It is noted that in the illustratedconfiguration of FIGS. 1a -5 b, the tip of the surgical instrument maybe assumed to be substantially close to a tip of the instrumentmanipulator and hence surgical instrument is not separately indicatedhere. In general, however, there might be any desirable distance betweenthe tip of the surgical instrument and the tip of the instrumentmanipulator.

It should be noted that in general, 2D or 3D configurations other thanthose illustrated herein may be possible for obtaining a desiredmovement of the instrument manipulator.

It is further noted that the movement of the instrument manipulator maybe obtained as a result of a force, e.g. gravity force and/or springforce, acting upon the instrument manipulator when desired, e.g. when arelease mechanism releases the instrument manipulator. In a furtherexample, at least one of the first linkage component and the secondlinkage component may be provided with a manual actuation handle forenabling a user to manually actuate the linkage system so as to move therespective suspension point of the instrument manipulator along therespective movement trajectory. Various types of handles are known inthe art per se. The handle may include a handgrip. It is noted that suchan actuation handle may be used to put the instrument manipulator backin place at the surgical position by, e.g., pushing the instrumentagainst gravity. In a further example, the surgical master-slave robotmay also include an actuator for actuating the linkage system so as tomove the respective suspension points of the instrument manipulatoralong the respective movement trajectory.

FIG. 6a shows a release mechanism 700 for holding and releasing theinstrument manipulator at a surgical position. The release mechanism maybe affixed to the robot (not shown) and may be coupled to the instrumentmanipulator. By use of the release mechanism 700, the instrumentmanipulator may be allowed to be released and then move sideways. Therelease mechanism 700 may include a hook 701, a lock arm pin 703, and arelease actuator 704. The hook 701 may be arranged and configured forgripping the lock arm pin 703. It is noted that the hook may also bereleased manually. The lock arm pin may be connected to one of the firstlinkage component, the second linkage component or the instrumentmanipulator via a lock arm 702. The release actuator 704 may be arrangedand configured for releasing the hook 701 from the lock arm pin 702.FIG. 6b shows the release mechanism 700 when the release actuator 704releases the hook 701 and thereby releases the instrument manipulatorvia the lock arm 702. When released, a drive torque may put theinstrument manipulator into motion. Such torque may be applied passivelyby, e.g., use of storage of potential energy, via either a preloadedtorsion spring or by the instrument manipulator's center of gravity. Itis noted that the hook 701 may be preloaded via a spring 705 so that anengagement between the hook 701 and the arm lock pin 703 may be enabledwhen the lock arm 702 advances towards the quick release lock. Whenlocked, the pin of the lock arm may be fixated, using a three-pointconnection further held in place by the hook 701. This may enable theinstrument manipulator to be repositioned back into place with highaccuracy. It is noted that the robot may include an actuator (not shown)for actuating the linkage system for repositioning of the instrumentmanipulator.

FIG. 7a shows an example of a configuration and construction of arelease mechanism 800. The release mechanism 800 may include a firstbore 810 in which two bearing balls 812 are positioned. The releasemechanism 800 may further include a second bore 814 in which a referencepin 816 may be placed orthogonally and slightly offset. The bearingballs 812 may force against the reference pin 816, and as such, thebearing balls 812 may be precisely located. The bearing balls 812 mayform a V-shaped reception 818 of a lock arm pin 803 of a lock arm 802.The V-shaped reception 818 may enable an accurate repositioning of theinstrument manipulator. When locking, the lock arm pin 803 may beengaged into the V-shaped reception 818. The lock arm pin 816 may beenclosed by a release hook 801 and thus a three point constraint may berealized that may constrain the lock arm 802 in an X-Y plane only. Thelock arm 802 may include a leaf spring or have a leaf spring shape (notshown) providing a compliance so as to enable the lock arm pin 803 toslide all the way into the V-shape reception 818. The bearing balls 812and the pins 803, 816 may be made of hardened steel.

FIG. 7b shows a 3D isometric view of the release mechanism 800 of FIG. 7a.

FIG. 8 shows another aspect of the claimed surgical robot, namely acannula connector 902 for coupling to a cannula 903, the cannulaconnector 902 providing a through passage 950 for a surgical instrument904 to enter an interior of a tissue, e.g., any eye of a subject for,e.g., eye surgery. In The cannula 903, also known as trocar in somesurgical applications, may have on the proximal end an interface to thecannula connector 902 and on the distal end a tube that may be placed inan incision, e.g., the sclera in eye surgery. For example, in eyesurgery, the cannula 903 may provide an opening or access point forvitreoretinal instruments to enter the eye. During surgery, multiplecannulas may be used, e.g., one for an infusion, one for a light fiberand one for an articulated instrument). The surgeon may use a microscopeto look through the pupil inside the eye, seeing the surgical instrumenttips.

The cannula connector 902 may be coupled at a proximal end to aninstrument manipulator 910 of a surgical robot. For example, the cannulaconnector 902 may be coupled to the instrument manipulator 210 of thesurgical robot 100 of FIG. 1 c. The cannula connector 902 may be shapedto fit a shape of the cannula 903 so as to establish a releasablecoupling with the cannula 903 which releases when the instrumentmanipulator 910 moves away from an entry surface on the eye 10 of thesubject in a substantially perpendicular direction 960. The cannula 903and the cannula connector 902 may be made of medical grade materials:such as a selective group of stainless steel, titanium or plastics suchas PEEK.

It is noted that in an example, the manipulator may be pushed onto thecannula with a predefined force. This force may be actively measuredusing a force sensor inside the cannula connector. In a further example,active mechanical clamping and releasing of the cannula may be used.When removing the instrument manipulator away from the area for surgery,the cannula may be loosening automatically. It is noted that activemagnets may be also used which may be switched on and off automatically,to connect/disconnect the cannula to the cannula connector. Vacuum maybe also used to suck to cannula to the cannula connector.

It should be noted that the above-mentioned embodiments illustraterather than limit the presently disclosed subject matter, and that thoseof ordinary skill in the art will be able to design many alternativeembodiments without departing from the scope of the appended claims. Inthe claims, any reference signs placed between parentheses shall not beconstrued as limiting the claim. Use of the verb “include” and itsconjugations does not exclude the presence of elements or stages otherthan those stated in a claim. The article “a” or “an” preceding anelement does not exclude the presence of a plurality of such elements.Some embodiments may be implemented by hardware including severaldistinct elements, and by a suitably programmed computer. In the deviceclaim enumerating several devices, several of these devices may beembodied by one and the same item of hardware. The mere fact thatcertain measures are recited in mutually different dependent claims doesnot indicate that a combination of these measures cannot be used toadvantage.

The invention claimed is:
 1. A surgical master-slave robot for use witha surgical instrument in minimally or reduced invasive surgery on asubject, the surgical master-slave robot comprising: an instrumentmanipulator for mounting of the surgical instrument; and a linkagesystem for moveably suspending the instrument manipulator, the linkagesystem including: a first linkage component coupled to the instrumentmanipulator at a first suspension point of the instrument manipulator;and a second linkage component coupled to the instrument manipulator ata second suspension point of the instrument manipulator; wherein: thefirst linkage component is configured for guiding the first suspensionpoint of the instrument manipulator to move along a first movementtrajectory; and the second linkage component is configured for guidingthe second suspension point of the instrument manipulator to move alonga second movement trajectory; and the first movement trajectory and thesecond movement trajectory differ and are selected to provide a combinedtranslational and rotational movement of the instrument manipulatorwhich moves the instrument manipulator along a predefined trajectoryfrom a surgical position proximate to the subject to a standby positiondistal to the subject, wherein the surgical master-slave robot includesa release mechanism for holding and releasing the instrument manipulatorat the surgical position, wherein the release mechanism includes alocking mechanism which locks the instrument manipulator into positionat the surgical position and an actuator for unlocking the lockingmechanism to release the instrument manipulator from the surgicalposition; and wherein the movement of the instrument manipulator fromthe surgical position to the standby position is obtained as a result ofa force acting upon the instrument manipulator when the releasemechanism releases the instrument manipulator, wherein the force isgenerated passively by conversion of stored potential energy.
 2. Thesurgical master-slave robot according to claim 1, wherein the movementof the instrument manipulator causes a tip of a distal end of theinstrument manipulator to move along a third movement trajectory, andwherein an end portion of the third movement trajectory proximate to thesubject is oriented in a direction perpendicular to a surgical entrysurface of the subject.
 3. The surgical master-slave robot according toclaim 2, wherein the surgical master-slave robot further includes acannula connector for coupling to a cannula, wherein the cannulaprovides an opening at the surgical entry surface of the subject for thesurgical instrument to enter an interior of the subject, and wherein thecannula connector: is coupled to the instrument manipulator at aproximal end; includes a through passage for allowing the surgicalinstrument to pass through the through passage; and is shaped to fit ashape of the cannula so as to establish a releasable coupling with thecannula which releases when the instrument manipulator moves in thedirection perpendicular to the surgical entry surface of the subject. 4.The surgical master-slave robot according to claim 3, wherein thecannula -has a conical shape, and wherein the cannula connector isconically shaped to fit the conical shape of the cannula.
 5. Thesurgical master-slave robot according to claim 4, wherein the cannulaconnector is capable of being rigidly coupled to the cannula.
 6. Thesurgical master-slave robot according to claim 3, wherein the cannulaconnector is capable of being rigidly coupled to the cannula.
 7. Thesurgical master-slave robot according to claim 2, wherein the standbyposition is located laterally sideways with respect to a sagittal planeof the subject and the linkage system is configured for guiding theinstrument manipulator laterally sideward with respect to the sagittalplane during the movement from the surgical position to the standbyposition.
 8. The surgical master-slave robot according to claim 2,wherein the standby position is located lower than the subject, and thelinkage system is configured for guiding the instrument manipulatordownward with respect to a coronal plane of the subject during themovement from the surgical position to the standby position.
 9. Thesurgical master-slave robot according to claim 2, wherein the linkagesystem is provided with a manual actuation handle for enabling a user tomanually actuate the linkage system so as to move the respectivesuspension point of the instrument manipulator along the respectivemovement trajectory.
 10. The surgical master-slave robot according toclaim 2, wherein the surgical master-slave robot includes an actuatorfor actuating the linkage system so as to move the respective suspensionpoint of the instrument manipulator along the respective movementtrajectory.
 11. The surgical master-slave robot according to claim 2,wherein at least one of the first linkage component and the secondlinkage component includes or is constituted by a slider for slidingalong a guide shaped to establish the respective movement trajectory.12. The surgical master-slave robot according to claim 2, wherein thefirst linkage component and the second linkage component each are rodmembers rotatable about a respective rotation point and having differentlengths, and a rotation of the first linkage component and the secondlinkage component about the respective rotation points provides themovement of the respective suspension point along the respectivemovement trajectory.
 13. The surgical master-slave robot according toclaim 1, wherein the standby position is located laterally sideways withrespect to a sagittal plane of the subject and the linkage system isconfigured for guiding the instrument manipulator laterally sidewardwith respect to the sagittal plane during the movement from the surgicalposition to the standby position.
 14. The surgical master-slave robotaccording to claim 1, wherein the standby position is located lower thanthe subject, and the linkage system is configured for guiding theinstrument manipulator downward with respect to a coronal plane of thesubject during the movement from the surgical position to the standbyposition.
 15. The surgical master-slave robot according to claim 1,wherein the force is generated by gravity and/or a preloaded spring. 16.The surgical master-slave robot according to claim 1, wherein thelocking mechanism includes a hook and a lock arm pin, wherein: the hookis arranged and configured for gripping the lock arm pin; the lock armpin being connected to one of the first linkage component, the secondlinkage component or the instrument manipulator via a lock arm; and theactuator is arranged and configured for releasing the hook from the lockarm pin.
 17. The surgical master-slave robot according to claim 1,wherein the linkage system is provided with a manual actuation handlefor enabling a user to manually actuate the linkage system so as to movethe respective suspension point of the instrument manipulator along therespective movement trajectory.
 18. The surgical master-slave robotaccording to claim 1, wherein the surgical master-slave robot includesan actuator for actuating the linkage system so as to move therespective suspension point of the instrument manipulator along therespective movement trajectory.
 19. The surgical master-slave robotaccording to claim 1, wherein at least one of the first linkagecomponent and the second linkage component includes or is constituted bya slider for sliding along a guide shaped to establish the respectivemovement trajectory.
 20. The surgical master-slave robot according toclaim 1, wherein the first linkage component and the second linkagecomponent each are rod members rotatable about a respective rotationpoint and having different lengths, and a rotation of the first linkagecomponent and the second linkage component about the respective rotationpoints provides the movement of the respective suspension point alongthe respective movement trajectory.